Alligator Bioscience

Regulatory Filings • Nov 6, 2019

ATOR-1017 Induces Long-Lasting Immunity – New Preclinical Data to be presented at SITC 34th Annual Meeting

Lund, Sweden, November 6, 2019 – Alligator Bioscience (Nasdaq Stockholm: ATORX), today announced that the company will present new preclinical data showing that their drug candidate ATOR-1017 can induce a long-lasting immunological memory which is of great importance in a potential future patient setting. The results will be presented at the ongoing Society for Immunotherapy of Cancer (SITC) 34th Annual Meeting. The ATOR-1017 drug candidate is in development for the treatment of metastasized cancer.

Furthermore, the results show that treatment with ATOR-1017 activates the immune system in the tumor area but not systemically. These preclinical data support a tumordirected activity of ATOR-1017. The aim is to focus the immune attack towards the tumor in order to increase efficacy and minimize side effects for the patient. ATOR-1017 is currently about to initiate Phase I clinical study and dosing of the first patient is expected shortly.

"These preclinical data support the potential of ATOR-1017 to generate a strong and longlasting immune response or even to induce immunity to cancer. This is our fourth asset to enter the clinic and with its unique tumor-directed profile, we continue to build a clinical pipeline of the next generation cancer immunotherapies", said Per Norlén, CEO of Alligator Bioscience.

The upcoming Phase I study will be a first-in-human, dose escalation study in patients with advanced cancer. It will be conducted at three sites in Sweden and will enroll up to 50 patients. The primary objective of the study is to assess the safety and tolerability of ATOR-1017 and to determine the recommended dose for the subsequent Phase II studies.

Karin Enell Smith, Senior Scientist at Alligator Bioscience will present a poster with the title "ATOR-1017, a 4-1BB antibody developed for tumor-directed immunotherapy of cancer" on Saturday November 9 at the SITC 34th Annual Meeting held in National Harbor, Maryland, US. The poster presentation will be available on the Alligator web site www.alligatorbioscience.com on the day of the presentation.

For further information, please contact:

Cecilia Hofvander, Director Investor Relations & Communications Phone +46 46 540 82 06 E-mail: cecilia.hofvander@alligatorbioscience.com

The information was submitted for publication, through the agency of the contact person set out above, at 2:00 p.m. CET on November 6, 2019.

About ATOR-1017

ATOR-1017 is an immunostimulatory IgG4 antibody that activates tumor-specific T cells and NK cells through the costimulatory receptor 4-1BB. T cells and NK cells have the capacity to detect and kill tumor cells, making 4-1BB a particularly attractive target for cancer immunotherapy. ATOR-1017 has a unique profile related to the fact that its immunostimulatory function is stronger in areas where immune cells are abundant, notably in tumors. This creates an opportunity for a strong immune activation, while minimizing side effects for the patient.

About Alligator Bioscience

Alligator Bioscience AB is a clinical-stage biotechnology company developing tumordirected immuno-oncology antibody drugs. Alligator's growing pipeline includes six lead clinical and preclinical drug candidates: mitazalimab (ADC-1013), ATOR-1015, ATOR-1017, ALG.APV-527 (co-developed with Aptevo Therapeutics Inc.), ATOR-1144 and AC101 (in clinical development by Shanghai Henlius Biotech Inc.). Alligator's shares are listed on Nasdaq Stockholm (ATORX). The Company is headquartered in Lund, Sweden, and has approximately 55 employees. For more information, please visit www.alligatorbioscience.com.